1. Field of Invention
The invention relates to an ink jet recording apparatus that records recording media such as sheets of paper, by ejecting ink onto them.
2. Description of Related Art
Conventionally, an ink jet recording apparatus, for example, is known as a recording apparatus that produces records of prints by ejecting ink onto a recording medium such as paper. The ink jet recording apparatus is provided with a purge apparatus that sucks waste ink including air bubbles generated in the ink jet head.
The purge apparatus is provided so as to move between a stand-by area and a recording area. For example, FIG. 4 shows the conventional purge apparatus which includes a suction cap 3 that covers a nozzle surface of an ink jet head 1, a cap holder 4 that holds the suction cap 3, and two adapters 7 (hereinafter referred to as a suction-side adapter 7a and an air-communicating side adapter 7b, if a distinction is needed) that connect a suction tube 5 and an air-communicating tube 6 with the suction cap 3 via the cap holder 4.
The suction cap 3 is made of an elastic member such as rubber and has a substantially rectangular shape. The suction cap 3 has an abutting portion 17 and a recess 8 on the surface, and two holes 16 for inserting the two adapters 7 on the back.
The cap holder 4 is made of resin and internally formed with peripheral side wall 9 and a bottom wall 10, which is shaped like a letter H in a sectional view. The surface of the suction cap 3 where the recess 8 is formed is held open, the rear surface of the suction cap 3 is brought into intimate contact with the bottom wall 10, and the periphery of the suction cap 3 is brought into intimate contact with the peripheral side wall 9. Thus, the cap holder 4 elastically maintains the suction cap 3 therein.
Each of the two adapters 7 is shaped in a pipe passing through the bottom wall 10 of the cap holder 4, and includes a front side protruding portion 14 that protrudes from a front surface of the bottom wall 10 and a rear side protruding portion 15 that protrudes from a rear surface of the bottom wall 10, which are integral with the cap holder 4.
Each front-surface protruding portion 14 is elastically inserted into the corresponding hole 16 formed in the suction cap 3, so that the two adapters 7 are connected to the suction cap 3 in a sealed state.
The suction tube 5 is connected with the rear-surface protruding portion 15 of the suction-side adapter 7a at one end and the suction pump 11 at the other end. The air-communicating tube 6 is connected with the rear-surface protruding portion 15 of the air-communicating side adapter 7b at one end, and released to air at the other end. The solenoid 12 is disposed in the middle of the air-communicating tube 6 so as to open and close the air-communicating tube 6 in accordance with a back-and-forth movement of the plunger 13.
During purge operation, the nozzle surface 2 of the ink jet head 1 is disposed in face-to-face relation with the suction cap 3. With the upward motion of the suction cap 3, the abutting portion 17 makes contact with the nozzle surface 2, and the airtight space 18 is formed between the recess 8 and the nozzle surface 2. When the suction cap 3 makes contact with the nozzle surface 2, the air-communicating tube 6 is previously released to air to prevent compressed air from entering nozzles. The plunger 13 of the solenoid 12 is advanced to close the air-communicating tube 6. The suction pump 11 is activated to suck waste ink in the ink jet head 1 from the suction cap 3 via the suction tube 5 and the suction side adapter 7a. 
In the purge apparatus, the two adapters 7 are integral with the cap holder 4. To reliably seal between the suction cap 3 and the two adapters 7, it is necessary to accurately form diameters of the front-surface protruding portions 14 of the two adapters 7 and the diameters of the two holes 16 of the suction cap 3. Further, it is necessary to accurately produce a pitch X between the two front-surface protruding portions 14 of the adapters 7, and a pitch Y between the two holes 16 of the suction cap 3, so as to align with each other. However, to reproduce the pitches X and Y accurately takes a lot of trouble, leading to an increase in parts cost.
The invention provides an ink jet recording apparatus having a purge apparatus that can ensure reliable sealability between a suction cap and a connecting member which are simply and reliably connected via a cap holder.
According to one aspect of the invention, an ink jet recording apparatus includes an ink jet head and a purge apparatus. The ink jet head includes a plurality of nozzles that eject ink onto a recording medium, and a nozzle surface on which the nozzles are arranged. The purge apparatus sucks ink in the ink jet head therefrom. The purge apparatus includes a plurality of connecting tubes, a suction cap that covers the nozzle surface of the ink jet head, a cap holder that holds the suction cap, and an at least one connecting member that connects the suction cap and at least one of the connecting tubes.
According to another aspect of the invention, an ink jet recording apparatus includes an ink jet head and a purge apparatus. The ink jet head includes a plurality of nozzles that eject ink onto a recording medium, and a nozzle surface on which the nozzles are arranged. The purge apparatus sucks ink in the ink jet head therefrom. The purge apparatus includes a plurality of connecting tubes, a suction cap that covers the nozzle surface of the ink jet head, a cap holder that holds the suction cap and includes a connecting portion that connects the suction cap and a first connecting tube of the connecting tubes, and a connecting member that is supported in the cap holder and connects the suction cap and a second connecting tube of the connecting tubes.